Solutions for contact in pinned connections

The pinned connection is a principal joining and load-bearing element in countless structures. A comprehensive analytical solution for the mechanics of a pinned connection would greatly facilitate mechanics and dynamics analyses seeking to address larger issues such as fatigue life and earthquake resistance of entire structures. However, even the most advanced closed-form solutions describing contact conditions in pinned connections involve mathematical approximations for some or all of the following aspects of the problem: plate dimensions, contact area, pin-plate friction and material property mismatch. The actual problem involving a finite plate, frictional contact and arbitrary material pairs still remains intractable in a rigorous manner through elasticity theory. This study uses the finite element method to obtain solutions when some or all of the above simplifying assumptions are removed, and thereby also evaluates the general applicability of the most advanced closed-form solutions. A surprising finding is that the pin-plate contact pressure and plate tangential stress distributions are practically independent of the material pair as long as both the pin and plate are metallic and the friction coefficient is small. It is also found that the stress concentration factor in the plate is significantly higher when finite dimensions are considered. Among the factors considered, the pin-plate friction coefficient has the greatest effect on the contact pressure and tangential stress distributions. (C) 2001 Elsevier Science Ltd. All rights reserved.